This invention relates to an apparatus for reorienting yeast cakes by a tumbling operation and delivering the tumbled yeast cakes to a conveyor.
This invention may also be adapted for use in tumbling any regular rectangular prismatic articles selectively through a rotation of either 90 degrees or 180 degrees.
It is well-known and conventional in the packaging and assembly industries to rotate articles being processed. In some cases, the articles being processed must be rotated about an axis of the article in order to continue the manufacturing or packaging steps. In the packaging industry, for example, a package may be formed about an intermediate article and then folded along what is at that moment the top of the intermediate article. In packaging, it is not desirable generally to display articles with the folded portions of wrapping face-up. Therefore, these articles must be tumbled 180 degrees in order to rotate the folded side to the bottom position. In a manufacturing process, articles must be rotated or tumbled in order to bring a particular side into engagement with a particular machining or packaging step.
The prior art tumbling devices as described above have several drawbacks. Prior art tumbling devices generally are made of relatively complex, multi-stage devices requiring multiple conveyors, handlers, and support shelves. Furthermore, the prior art tumbling devices generally use more than a single reciprocating part and therefore are subject to breakdown, high maintenance requirements, and heavy capital investment requirements compared to the tumbling device of the present invention. Also, the prior art tumbling devices cannot tumble yeast cakes gently enough to avoid damage to the edges and corners of the yeast cakes.
When a stream of articles to be tumbled enters a tumbling area, it is convenient to tumble a plurality of articles simultaneously. It is also desirable that the tumbled articles then be immediately conveyed away from the tumbling area in as simple a step as possible. Some of the prior art tumbling devices cannot tumble a plurality of articles simultaneously.
Examples of prior art devices wherein multiple shelves and multiple conveyor belts are used to tumble articles include: Lewallyn in U.S. Pat. No. 4,130,048; U.S. Pat. No. 3,679,072 to Skiba, Jr.; Straight in U.S. Pat. No. 1,602,719; U.S. Pat. No. 3,144,120 to Neiheisel; and U.S. Pat. No. 2,387,674 to McIntire.
Lewallyn shows a carpet sample bevelling apparatus and method having multiple conveyor belts and multiple shelves. Here, relatively thin carpet samples are conveyed generally on edge. Conveyor belts are used to convey the samples from position to position so that, by a series of step conveyor belts, the sample is tumbled as it leaves a higher step conveyor belt to a lower step conveyor belt. As noted in the above, this type of device is generally complex, requires generally high maintenance, and requires a high capital investment initially. In Lewallyn, additional processing steps, i.e. bevelling, are used and therefore the overall device must be complex.
Skiba, Jr. shows a machine for package turnover and orientation. The packages or articles turned are rotated through approximately 180 degrees to present the package in position for further processing. Included are a plurality of pairs of chambers formed from sheet material and each chamber is a platform which is progressively retracted after the packages have been severed from web material. Under the influence of gravity, each package in turn tips during its departure from the associated chamber. A plurality of guides which generally form a chute-like path guide the article to a conveyor belt which takes the articles away for further processing. However, a single reciprocating part is not used to tumble the articles, nor is the device a simple one. In this instance, a chute is required as well as a means for separating packages formed from webbed material. Thus, the device and apparatus disclosed in Skiba, Jr. does not rotate packages through 180 degrees in a simple, reciprocating device but rather requires a multi-level conveyor chute which is only adapted to handle a single article at a time. Further, no provision is made in Skiba, Jr. for processing and conveying away a plurality of articles arranged in a linear column upon a conveyor belt.
Straight discloses a tile cutting machine including an endless conveyor together with an off-bearing mechanism for tile cutting. The tile as it is delivered from a horizontal position, is conveyed to a second conveyor belt in a vertical position. A gripper device is used to grip each tile as it passes by and rotated approximately 90 degrees releasing the tile upon a second conveyor belt which conveys the tiles away. However, no simple reciprocating member is shown for tumbling articles 180 degrees. Here, tumbling does not occur, but rather a guided movement through an arc of approximately 90 degrees takes place. The device of Straight is generally complex and capital intensive initially as compared to the present invention, and requires a relatively high degree of maintenance.
Neiheisel shows an article inverter which tumbles articles through a 180 degrees rotation. A stationary shelf is employed as an intermediate impact member in the tumbling operation. A first conveyor is used to provide articles to a series of idler rollers, a first roller being equal in width to that of the first conveyor but the remaining rollers being shorter and terminate at a point which bisects the article to be turned at a point inwardly of its center of gravity. Thus, the article is turned under the influence of gravity about its center of gravity such that it rotates as it falls. This device is generally complex in that the series of rollers and the conveyors belts provided, as well as the intermediate tumbling shelf, requires movement of a plurality of articles including movement of each individual roller and therefore relatively high maintenance requirements are present. Also, a single reciprocating part is not used to tumble the articles. Furthermore, the tumbling operation disclosed by Neiheisel takes place during a single tumbling step which incurs relatively large impact forces since the fall of the tumbled article is not broken at a 90 degrees rotation but rather the tumbling article continues on through the entire 180 degrees rotation in a single step. Thus, the tumbling is less well controlled and the impact forces are correspondingly larger.
McIntire discloses a cleat turner and grading table. Here, articles are rotated through a 90.degree. rotation. Here, two separate conveyor belts are used together with an upwardly-sloping surface which provides an initial height through which the articles to be tumbled can fall. The articles to be tumbled fall by being pushed across a sharp corner of the upwardly-sloping surface and fall upon the second conveyor belt. Articles arriving on the first conveyor belt are used to push leading articles up the upwardly-sloping wall so that they are forced to tumble upon the second conveyor belt. However, no rotation through 180 degrees is taught or suggested by McIntire. Furthermore, no reciprocating member is shown in McIntire to complete rotation of articles through 180 degrees. Although the device of McIntire is generally simple, only a 90 degrees rotation is accomplished.
Other types of tumbling devices are also known. One example is that disclosed by Hinchliffe in U.S. Pat. No. 3,160,287. Here an apparatus for inspecting objects employs a plurality of stationary members cooperating with a plurality of pivotably rotating members. A single elongated article is rotated and moved forwardly along the stationary portions of the apparatus by the moving portions of the apparatus. The moving portions of the apparatus have a jagged tooth section such that while moving upwardly the articles to be rotated are not supported directly under their center of gravity but rather tend to tip about one of the jagged portions and rotate through an angle of less than 90 degrees. During subsequent steps, the moving portion deposits the article upon the stationary portion. The process is repeated until all four sides of the article can be inspected. However, the device of Hinchliffe is generally complex and requires a relatively large capital investment. Moreover, no single reciprocating part is used to accomplish a rotation through 180 degrees. Also, in Hinchliffe, the article repeatedly falls and is lifted again so that its overall path is that of a level zig-zag line. Thus, no overall fall through a vertical height is employed in Hinchliffe. Furthermore, the maintenance requirement of the device in Hinchliffe would be substantial due to the large number of moving parts.
Another type of package turnover device is shown in Renney in U.S. Pat. No. 2,370,325. There, packages of gum are rotated through a 180 degrees rotation by a device which includes various blocks disposed along a level horizontal supporting table along with a pair of conveyor belts which convey articles to be tumbled by frictional gripping action between the opposed conveyor belts. Thus, forward motion of gum packages is caused by opposite gripping forces exerted by moving conveyor belts which advance the gum package articles along a generally level path. Interposed in this generally level path is an initial drop from a first surface to a second surface which causes tumbling rotation of the gum package article through 180 degrees. A second block elevated above the second surface causes further tumbling of the gum package article through an additional 90 degrees rotation. However, the device of Renney does not use a single reciprocating member to tumble an article through 180 degrees, but rather uses a complex pair of conveyor belts straddling a central support shelf and article path. Thus, maintenance requirements would generally be high in the device of Renney due to the requirement that the articles tumbled be gripped along opposing sides. Furthermore, a relatively large capital investment would be required by the device of Renney in that motive force for the two rotating conveyor belts is required, as well as precise alignments between all of the parts to insure the proper frictional gripping action which is still not sufficiently strong as to prevent tumbling of the articles. Also, no net drop in height occurs of the articles to be tumbled in Renney, which also differs from the present invention.
A further type of device is that shown in Miguel in U.S. Pat. No. 4,302,141. A bale destacker is disclosed which employs a chute, side-gripping conveyor means, and an initial vertical drop to rotate bales through 90 degrees. However, the device of Miguel is generally complex and does not in any event rotate the bales 180 degrees. Furthermore, a plurality of articles cannot be simultaneously tumbled so as to be conveyed away in a linear row of articles but rather single articles must be delivered.